Cover the tea tray with a linen or a doily. Make sure the cloth is the exact size of the tray area on the inside of the rim. Don't cut a cloth to match the tray; rather, purchase or make a linen that fits your tray, whether it's rectangular or oval.
Stack saucers. Place one cup, on its side, handle out, to one side on top of the saucer stack. Turn the second cup on its side and put the side opposite its handle into the mouth of the first cup. Place the third cup into the second cup in the same way, and the fourth into the third. The resulting circle of teacups is loosely hooked together, sitting atop the saucers. Place the entire stack on the upper left side of the tray, as it's oriented to you.
Fold each napkin in half diagonally. Stack them and place the stack to the immediate right of the cups and saucers. Fan the napkins out slightly.
Put teaspoons on top of the napkins with their handles toward the edge of the tray.
Fill the milk pitcher three-quarters full with milk. Place it directly to the right of the napkins with its handle toward the right edge of the tray.
Fill the sugar bowl. Put the lid on and set it next to the milk pitcher, along the right edge of the tray.
Place an insulated carafe filled with extra hot water between the sugar bowl and the cups and saucers.
Put the teapot, filled with hot water and steeping tea, along the left edge of the tray just behind the cups and saucers. Make sure the handle is toward you at the back edge of the tray.
Place a small vase of fresh flowers in the final empty space, just behind the sugar bowl. Fill the vase with water half-way to prevent it from spilling.